Stencil



Feb. 16 1926. 1,573,082

H. DE F. MADDEN STENCIL Filed Sept. 16, 1921 INVENTOR HARRY D, MA DDEN ATTORNEY Patented Feb. 16, 1926.

UNITED STATES PATENT OFFICE.

HARRY DE FOREST MADDEN, OF NEWARK, NEW JEBSEY ASSIGNOR TO WESTING- I HOUSE LAM]? COMPANY, A CORPORATION OF PENNSYLVANIA.

STENCIL.

Application filed September 16, 1921. Serial No. 501,126.

To all whom it may concern:

Be it, known that I, HARRY DE FOREST MADDEN, a citizen of the United Stateaand a resident of Newark, in the county of Essex and State of, New Jersey, have invented a new and useful Improvement in Stencils, of which the following is a specification.

This invention relates to stencils employed in lettering and ornamenting articles,

and it has for its primary object the provision of an improved stencil constructed to withstand the wearing action of the material employed to react with the surface of an article to be marked.

A further object is to provide a stencil with a resilient protective coating which prevents an operating or abrasive material from Wearing away the small projecting ends and cross bonds created in the stencil body when a pattern is formed therein. 1

It has been. found by experience that the life of a stencil is usually dependent upon its ability to withstand the wearing action of the material which is employed to score the surface of the article to be inscribed. This is especially true of metal stencils, as the small ends and cross bonds are worn away at a very rapid rate, thus necessitating the closing down of the machines at frequent intervals during working hours to make necessary stencil replacements. "The loss due to the idleness of the machines also means a loss due to the idleness of the operators. These losses, when taken with 1 the cost of the large quantity of stencils required, increase the operative cost of the machines beyond a value commensurate with the results accomplished.

'My invention contemplates the use of an improved stencil which materially reducesv the cost of operation of a stenciling machine and which permits a larger number of articles to be marked before stencil replace ments are required. I x

In the accompanying drawings, which form a part of this specification, Fig. 1 is a top plan view of a selected stencil having a pattern formed therein;,

Fig. 2 is asectional view taken on the line II-II of Fig. 1; I

Fig. 3 is, a sectional viewtaken on: the line TIL-III of Figflyand Fig. 4 is an elevational v ew showing, in

section, my improved stencil mounted in a stencilin machine.

Referring now to the drawings, the

selected embodiment is of a stencil generally employed-for marking or forming legends on the bulbs of incandescent lamps by having sand or other abrasive material blown against the stencil. The preferred construction of my improved stencil is best appreciated' by reference to Figs. 2 and 3 wherein the stencil is shown as being composed of a flexible metal body 1 and a resilient member 2 afiixed to the metal body in any desired manner. The resilient member, usually a sheet of rubber, may cover only a portion of the metal body but it is preferred to have it cover the whole surface, as illustrated. y Y

A desired pattern is formed in the stencil by punching out certain portions thereof in the usual manner, and, for the purposes of this description, the pattern takes the form of one of the letters of the alphabet. The punching operation is usually performed after the resilient coating has been affixed to the metal body. If desired, however, the metal body may be punched first and the resilient member afiixed after given openings have 'been formed therein.

In manufacturingthe stencils, the formation of'the patterns create smallprojecting ends 3 and connecting or cross bonds 4 which are very small in size in relation to the other portions of the stencil. Stencils heretofore manufactured have not had a protecting means for these small ends and bonds, and, consequently, they have-been rapidly worn away by the abrasive material, thus enlarging the openings of-the pattern to such an extent that the markings oIi the surface of articles become blurred and unintelligible.

In providing a protection of resilient nature to one side ofthe metal body, the

small ends and bonds are not subjected tothe scoring action of the abrasive material, and, therefore, clear-cut patterns are formed on the articles, and, in addition, the life of the stencil is materially increased. It will be'appreciated that, by increasing the life of the stencil, a stenciling machine may be maintained in continuous o eration for a materially lon er time, there y reducing the idle time 0 machines and operators,

The use of these long-life stencils permits replacements to be made during the shutdown hours of the factory.

The manner in which the improved stencil is mounted in a stenciling machine is illustrated in Fig. 4. A portion 5 of a machine is shown having therein openings 6 through which ends 7 of the stencil may be inserted and bent to firmly hold the stencil in normal curved position. The unprotected surface of the stencil is engaged by a lamp bulb 8 and the flexibility of the metal permits the stencil to conform to the curved surface of the bulb. The cutting or abrasive material may be brought into contact with the lamp bulb and stencil in any desired manner but I prefer to have it blown by air under pres sure through guiding conduits 9. The par ticles 0f the abrasive which pass through the stencil openings score the surface of the lamp and form the desired marking or pattern thereon. The particles which do not make contact with the lamp bulb are buffeted by the rubber and thus are not permitted to wear or affect the metal body.

The use of resilient coatings is much more desired than a harder substance, such as fibre, as the harder substance reduces the flexibility of the stencil, thus preventing the article to be marked from being moved into afirm and complete contact with the stencil. I have found that, by employing a stenoil of the improved construction, the length of life of the stencil is increased about 300% and I am thus enabled to maintain each stenciling machine in continuous operation during full working hours.

Modifications and changes in the construc tion of the stencils will be apparent to those skilled in the art, but such modifications and changes are considered as being within the scope of my invention, asdefined in the appended claims.

- What is claimed is:

1. A removable stencil having a pattern formed therein and having a resilient'matesubscribed my name this 15th day of rial adjacent to the edges of said pattern and adapted to arrest thewearing away of the pattern 'by a cutting material.

; 2. A removable stencil for use in marking articles. by an abrasive material comprising a metal body having a pattern formed therein and a resilient material aflixed .to the ex posed surface of said body for preventing said abrasive material from making contact with said metal body.

3. A removable stencil for use in marking articles by sand blast comprising a metal body having a pattern formed therein and a resilient material afiixed to the exposed surface of said body for preventing an abrasive material from making contact with said body.

4. In a rigid removable stencil for marking articles by sand blast, a resilient layer upon the exposed surface of said stencil for protecting those portions of the stencil adjacent to the openings therein from the action of a cutting material.

5. A stencil comprising a rigid metal body having openings therethrough'and a rubber coating associated with one surface thereof and having openings therein corresponding to the openings in said body, said coating being adapted to prevent an abrasive material from making contact with said body, said stencil being adapted for removal after use.

6. A stencil adapted for use in sand-blast machines composed of a thin rigid removable metal body having a symbol punched therein and a rubber coating aflixed to said body and having openings therein corre sponding to the openings in said body, said rubber being adapted to absorb the shock of the sand particles impinging tliereagainst, whereby Wear upon the edges of the symbol is materially reduced.

..In testimony whereof, I have hereunto September 1921.

HARRY DE FOREST MADDEN. 

